50 Cent's sudden absence from Chris Brown's tour promos is is because they couldn't come to terms on the money.

Sources connected to the tour say 50 was all in to be the lead guest on The Party Tour after initial talks with Chris' camp, where both sides agreed on his fee for the gig. Live Nation also assumed 50 was in and began putting his name and image on promotional materials.

When it was time to sign on the contract Live Nation and 50 were "hundreds of thousands of dollars apart" on terms.

There was an attempt to negotiate but 50 walked 2 weeks ago. The tour continued to be hyped with 50 for at least another week.

Some fans say they are pissed, claiming they bought tickets just to see Mr. Cent. The tour kicks off Friday in Baltimore, and no refunds will be given because Chris, the headliner, will be there as scheduled.